The proposed study uses multiple years of panel data from the National Longitudinal Survey of Youth (NLSY79, 1979-1998; n=8,461 in 1996) to conduct a comprehensive analysis of the implications that early and continuing illicit drug use have for the economic productivity of individuals. Economic productivity is measured by wage profiles, spells and duration of unemployment, job turnover, job training and promotion, and reliance on government assistance programs. Although several studies have examined the effects of drug use on some of these outcomes, there has been a lack of attention to long-term effects. The NLSY79, one of the most widely data sets designed specifically to examine economic productivity in the United States, has now followed multiple cohorts from their teenage years until their late thirties and early forties. This data set offers multiple measures of productivity and participation in the labor market, as well as a variety of measures of illicit drug use. The availability of these measures across a significant span of young and mid-adulthood make the NLSY79 ideal for investigating the long-term consequences of drug use over a substantial period of the individual economic life cycle. The specific aims of the proposed study are to assess the long-term effects of current and past illicit drug use on wage profiles, spells and duration of unemployment, job turnover, job training and promotion, and reliance on government assistance programs. Moreover, the study investigates the potentially sex-distinct effects of illicit drug use on these economic outcomes. The methods used to examine the long-term effects of drug use on economic productivity include longitudinal analysis techniques such as structural equation models, multilevel growth curve models, and fixed- and random-effects models. The results of the analyses will substantially enrich knowledge of the long-term consequences of illicit drug use on an important component of the life course.